Waking up with your heart racing can be distressing, but it’s not necessarily a sign of something serious. Anxiety, not sleeping enough, or heart arrhythmia may be the cause.

The racing sensation of your heart is just one way people describe heart palpitations. It may also feel like your heart is fluttering, pounding, or skipping a beat.

Heart palpitations are very common and usually harmless.

Several everyday things can make you wake up with your heart racing. But sometimes, an underlying condition may be the reason.

Read on to learn the causes and what you can do to calm your racing heart.

Having a fast heart rate in the morning can have many causes. Here’s a look at some common ones and other symptoms to watch out for.


Stress and anxiety trigger the release of stress hormones. These hormones, in turn, can increase your heart rate and blood pressure. A higher level of anxiety may cause more intense symptoms.

If you have depression or anxiety or are under a lot of stress, you may wake up with a racing heart from time to time.

Other common symptoms of anxiety can include:

Drinking alcohol the night before

If you’re waking up with your heart racing after drinking, chances are you’ve had too much.

Drinking alcohol increases your heart rate. The more you drink, the faster your heart beats. A 2017 study linked binge drinking and long-term heavy alcohol use with different types of cardiac arrhythmia, especially sinus tachycardia.

You may have other symptoms of a hangover hours after drinking. These may include:

  • headache
  • muscle aches
  • nausea
  • dizziness

These symptoms should clear up as your hangover subsides.


The sugar you consume is absorbed into your bloodstream after passing through your small intestine. Having too much sugar can cause a blood sugar spike. This signals your pancreas to release insulin and convert what it can to energy.

Your body may interpret an increase in blood sugar and energy as stress. This triggers the release of stress hormones.

Along with a racing heart, you may also begin to sweat. Some people also get what’s known as a “sugar headache.”

Processed sugar isn’t the only cause. Refined carbohydrates, such as white bread or pasta, can have the same effect, especially in people with diabetes.

Atrial fibrillation

Atrial fibrillation (AFib) is the most common type of irregular heart rate. It happens when the heart’s upper chambers beat out of coordination with the lower chambers.

AFib usually causes a fast heart rate, but some people feel a fluttering or thumping in the chest.

AFib itself isn’t usually life threatening. But in some cases, it can increase the risk of heart failure and may require treatment.

If you have AFib, you may also experience:

Sleep apnea

Sleep apnea is a sleep disorder in which breathing repeatedly stops and starts while you are asleep.

Obstructive sleep apnea is the most common type. It occurs when your throat muscles relax, causing your airway to narrow or close.

Research from 2018 suggests that sleep apnea increases the risk of an irregular heart rate. Sudden drops in your blood oxygen levels can raise your blood pressure and strain the cardiovascular system.

Symptoms of sleep apnea can include:


Caffeine is a natural stimulant commonly found in coffee, tea, and cacao plants. It stimulates the brain and central nervous system, which increases alertness.

In some people, too much caffeine can increase heart rate and blood pressure and cause anxiety and nervousness.

Consuming a large amount of caffeine-containing products can cause your heart to race. This includes products such as:

  • coffee
  • tea
  • soda
  • energy drinks

Drinking too much caffeine can cause other side effects. These may include:


Diabetes causes high blood glucose levels, which can damage the walls of your arteries and cause rapid heart rate, high blood pressure, and other heart-related complications. Research from 2019 suggests that having a rapid heart rate increases the risk of type 2 diabetes.

Other symptoms of diabetes include:

  • frequent urination
  • excessive thirst
  • extreme hunger
  • fatigue
  • tingling or numbness in the hands and feet
  • blurred vision

Medications containing stimulants

Just like caffeine, other stimulants can cause your heart to race. Stimulants may be ingredients in certain over-the-counter (OTC) and prescription medications.

These can include:

Hypoglycemia (low blood sugar)

Rapid heart rate can be a possible effect of low blood sugar, according to older 2014 research. Going a long time without eating can cause low blood sugar. Certain health conditions can also cause low blood sugar levels. These conditions can include:

Other symptoms of low blood sugar include:

Nightmares or night terrors

Nightmares and night terrors can cause you to wake up with a racing heart. Nightmares are disturbing dreams that can wake you up. Night terrors are a type of sleep disorder in which a person awakens partially in a state of terror.

Night terrors more commonly affect young children.

If you wake up after an upsetting dream or night terror with your heart racing, your heart rate should slow as you calm down.

Cold or fever

Any drastic change in your body temperature can cause changes in your heart rate. This includes cold temperatures and having a fever.

Your body reacts to a change in temperature by triggering processes to try to regulate your body temperature. This includes expanding and constricting your skin’s blood vessels. These mechanisms help keep heat in or carry it to the skin’s surface, causing muscle contractions and shivering.

Your heart rate can increase when your body works harder to keep its typical temperature. For many people, this is around 98.6°F (37°C).

Overactive thyroid

An overactive thyroid is also called hyperthyroidism. It occurs when your thyroid gland produces too much of the hormone thyroxine. It can accelerate your metabolism and cause a rapid or irregular heartbeat and unintentional weight loss.

Other symptoms you may notice include:

Lack of sleep

Along with many other negative effects on your body, 2018 research suggests that sleep deprivation can also increase your heart rate.

Aim to sleep 7 to 9 hours every night.

Not getting enough sleep can lead to:


Anemia occurs when you have too few healthy red blood cells in your body to carry the oxygen your organs and tissues need to work properly.

Anemia can occur when the body doesn’t make enough red blood cells or destroys them. People with heavy periods have a higher risk of anemia, too.

Along with arrhythmia, anemia can also cause:

  • fatigue
  • weakness
  • shortness of breath
  • headaches


Dehydration happens when the body loses more fluid than it takes in. When your body loses too much water, your cells and organs can’t function properly.

Dehydration can be mild or severe. If left untreated, it can cause serious complications.

Common symptoms of mild dehydration can include:

  • dry mouth
  • increased thirst
  • decreased urination
  • headache

Symptoms of severe dehydration may include:

Periods, pregnancy, and menopause

Fluctuating hormone levels can trigger feelings of a racing heart. This can include changes related to:

During the menstrual cycle, estrogen and progesterone levels rise and fall. The menstrual cycle can affect your heart rate, according to 2016 research. This can include episodes of a faster-than-typical heart rate called supraventricular tachycardia.

You may experience heart palpitations during pregnancy. The increased amount of blood in the body during pregnancy can cause your heart to beat 10 to 20 beats per minute faster than usual.

In perimenopause and menopause, the decrease in estrogen production is associated with an increased heart rate. This can cause frequent palpitations and nonthreatening arrhythmias.

Hot flashes can also trigger palpitations in menopause and cause your heart rate to increase.

Here are some other symptoms that can accompany waking up with a racing heart and what they could mean.

Waking up with a racing heart and shaking

Waking up with a racing heart and shaking may be caused by:

  • consuming too much caffeine
  • taking medications that contain stimulants
  • diabetes
  • hyperthyroidism
  • being cold
  • fever
  • a nightmare or night terror

Waking up with a racing heart and shortness of breath

Waking up with a racing heart and shortness of breath may be caused by:

  • anemia
  • AFib
  • sleep apnea
  • anxiety

Having a racing heart, chest pain, and dizziness

A racing heart, chest pain, and dizziness are warning symptoms of a heart attack. If you or someone else are experiencing these symptoms, call 911 or your local emergency services right away.

Medical emergency

A heart attack is a medical emergency and needs immediate medical treatment. Go to the nearest emergency room if you experience these symptoms.

A doctor or healthcare professional will begin by asking about your symptoms and performing a physical examination. They may listen to your heart and check for signs of conditions that can cause a racing heart such as an enlarged thyroid.

The doctor may also order one or more of the following tests:

A racing heart that’s infrequent and only lasts a few seconds doesn’t usually need evaluation. See a doctor if you have a history of heart disease or your palpitations worsen.

If you experience symptoms of a heart attack, look for emergency medical help or call 911 or your local emergency services. These symptoms may include:

Waking up with a racing heart often isn’t serious. It may not require treatment if it only happens occasionally or lasts just a few seconds.

But if your symptoms interfere with your daily activities or cause distress, you may want to see a doctor. They can rule out an underlying medical condition and help you find relief.